The present invention relates generally to a motor-fan assembly in an upright vacuum cleaner. More particularly, the present invention relates to a motor-fan assembly that directs the cooling air from the motor-fan assembly into a filter bag of a vacuum cleaner.
In the vacuum cleaner art, a motor-fan assembly is typically used as a vacuum source for drawing dirt laden air through a nozzle formed in the main body of the vacuum cleaner and directing that air into a filter bag. Known motor-fan assemblies, therefore, have a fan driven by a motor that draws the dirty working air into the motor housing and expels the dirty air through a motor fan outlet into the filter bag. To cool the motor, a cooling fan draws relatively cool air though an intake, across the components of the motor for cooling thereof before expelling the heated air out an exhaust vent. During its passage across the components of the motor, the cooling air may pick up particles discharged by the motor such as carbon or copper particles and carry these particles out the exhaust vent.
To prevent the venting of these particles into the atmosphere, it is known to route the cooling air into the working air intake, thus routing the cooling air into the filter bag along with the working air. In this manner, the particles discharged by the motor are captured in the filter bag. To perform the carbon capture, it is known to provide a vacuum cleaner motor within a fixedly mounted casing formed with a plurality of air inlets or vents. The motor drives a working fan which communicates with and draws air through a vacuum chamber. A channel extends between the motor housing compartment and the vacuum chamber creating a passage for the cooling air to be drawn into the vacuum chamber. As the working fan rotates within the fan compartment, a partial vacuum is created within the chamber which either by itself or in cooperation with a cooling fan draws the cooling air through the air inlets and is drawn into the motor casing to cool the motor. This air then flows through the channel into the vacuum chamber where it is discharged through a dirty air duct and into a vacuum cleaner filter bag.
Heretofore, these prior art arrangements that direct the cooling air, into the filter bag have been adequate for the purpose for which they are intended, however in many upright vacuum cleaners the motor-fan casing is attached to the upper housing of the vacuum cleaner and rotates relative to the foot of the vacuum cleaner. Because the prior art arrangements were incorporated into vacuum cleaners having a stationary motor-fan casing, these prior art arrangements are not suitable for uprights wherein the motor hosing rotates relative to the foot, as a constant communication must be maintained between the exhaust vents of the rotating motor casing and the stationary working air ducts of the foot.
Therefore, the need exists for an upright vacuum cleaner which directs cooling air from the motor-fan assembly into the filter bag yet permits rotational movement between the motor-fan casing and the foot.
The present invention, therefore provides, an improved vacuum cleaner having a main body and a handle. The main body being formed with a nozzle which delivers a stream of dirt-laden air through a dirt duct into a motor-fan inlet. The handle being supported on the motor-fan assembly and housing a dirt collecting container which communicates with the motor-fan assembly via an outlet for receiving the dirt-laden air. The motor-fan assembly includes a motor housing, a motor with commutator brushes which give off carbon dust particles, a motor cooling fan for drawing a cooling airstream and a working fan for drawing the dirt-laden airstream. An opening is formed in the motor housing for receiving the cooling airstream. A cooling outlet is formed in the motor housing through which the cooling airstream exits the motor housing. A duct directs the existing cooling airstream into the dirt-laden airstream and includes a sleeve extending axially outwardly from the motor housing. The sleeve allows for pivotal rotation of the motor housing relative to the main body.
The present invention further provides a motor fan assembly in a vacuum cleaner which includes a motor having commutator brushes located within a motor housing. The motor housing has a cooling inlet located near the commutator brushes, a working air inlet, and a working air outlet formed therein. The working air outlet fluidly communicates with the working air inlet and a working fan is positioned between the working air inlet and working air outlet. The working fan is driven by the motor wherein the working fan draws dirt laden working air into the motor housing through the working air inlet and blows the working air out of the motor housing through the working air outlet. A cooling outlet is formed opposite the working air inlet, wherein cooling air entering the cooling inlet exits the motor housing through the cooling outlet. A duct is rotatably supported on the motor housing adjacent said cooling outlet and communicates with the cooling outlet and the working air inlet, whereby air exiting the cooling outlet is directed into the dirt laden airstream and blown out the working air outlet to a dirt collecting container.
The present invention further provides a motor-fan assembly for a vacuum cleaner which includes a motor housing having a cooling air inlet, a working air inlet, and a working air outlet formed therein. The working air outlet fluidly communicates with the working air inlet. A motor is positioned within the housing having a motor shaft. A cooling fan is positioned adjacent the cooling air inlet and is coupled to the motor shaft. The cooling fan draws cooling air into the motor housing through the cooling air inlet to cool the motor. A working fan is positioned between the working air inlet and the working air outlet and is coupled to the shaft. The working fan drawing working air into the motor housing through the working air inlet and blows the working air out of the motor housing through the working air outlet. At least one hole is formed in the working fan allowing the cooling air to flow through the working fan and be blown out the working air outlet.